Process for the production of colored resists under aniline black by means of ester salts of leucovat-dyestuffs



Patented Oct. 20, 1936 UNITED STATES PROCESS FOR THE PRODUCTION OF COL- ORED RESISTS UNDER ANILINE BLACK BY MEANS OF ESTER SALTS OF LEUCO- VAT-DYESTUFFS Hans Tschumi, Basel, Switzerland, assignor to the firm of Durand & Huguenin A. G., Basel,

Switzerland No Drawing. Application January 7, 1936, Serial No. 58,022. In Germany January 14, 1935 9 Claims.

According to this invention colored resists under aniline black can be produced in an advantageous manner by applying the aniline black padding preparation to the white material, drying, then printing the material with a colored resist containing an alkali salt of a nonvolatile organic acid, an ester salt of a leuco-vat-dyestufi and aluminium chlorate, again drying and then steaming for about 2 minutes. By this short steaming operation not only the aniline black, but also the color of the resist is completely developed.

Two processes are already known by which colored resists can be produced under aniline black by means of ester salts of leuco-vat-dyestufis. According to the process described in German Specification No. 438,225 an ester salt of a leuco-vat-dyestufi together with a compound of acid reaction is printed on a fabric which has previously been padded with an aniline black preparation and dried. The development of the dyeing by oxidation occurs much more readily in the case of the ester salt than in the case of the aniline black, so that in consequence the ester salt itself acts as a resist. On steaming there is produced a desired result, that is, colored resists under aniline black. This process sufiers from the disadvantage that for developing respectively the aniline black and the leuco-ester (Indigosol) a difierent duration of the steaming operation is required. The aniline black color needs, for complete development, a steaming operation of 2-4 minutes; if this period is exceeded, there is danger of damage to the fibre. However, only very few ester salts are completely developed by this maximum duration of steaming for aniline black; for complete development of the ester salts 8-12 minutes steaming is generally required. Furthermore it is diflicult to determine exactly the required quantity of the compound of acid reaction. If too small a quantity is used the colored effects are insufficiently developed, whilst too large a quantity results in a defective resisting of the aniline black.

The further process described in German Specification No. 551,508 consists in printing on the white material an ester salt of a leuco-vatdyestuff together with one of the usual resists for aniline black. If required the material is steamed, the ground color of the aniline black is developed in known manner and finally the resist effects are developed by quite a short passage of the material through an acid bichromate bath followed by passage through the air; this treatment causes complete development of the ester salt dyeings without damage to the aniline black dyeings. This process is considerably more com plicated than that of the present invention. According to the latter process the material is subjected to one steaming operation whose duration is restricted to approximately 2 minutes, that is to say, that permissible for aniline black, whereby both the ground color and the color of the resist are developed completely in a manner free from objection.

It is to be noted that the development of the dyeing of the ester salt according to the present invention can be applied only to material which has been previously or subsequently padded with an aniline black preparation and cannot be applied on a white material, that is to say in direct printing.

The following examples illustrate the invention, the parts being by weight:

Examples 1, 2, and 3 A cotton fabric is padded with one of the customary aniline black padding solutions and dried. It is then printed with one of the follow- After the material has been dried it is steamed for about 2 minutes in a Mather-Flatt apparatus, then washed, treated with boiling soap solution and rinsed.

There are obtained respectively golden-yellow, orange and blue pattern effects on a black ground.

Examples 4 and 5 The material is printed as indicated above in the usual manner with an aniline black padding solution, dried and then printed with one of the following color resist printing pastes.

Parts Parts Ester salt of leuc0-4:4-dimethy1-6:6-dichlorothioindigo 30 Ester salt of leuco-5:6:7-trichlor0-5:7-dicliloroth1oindi o Ethylene-thioglycol 80 80 Urea 50 Water 150 Starch tragacanth thickening 500 500 Sodium citrate 100 Sodium lactate 100 Aluminium chlorate solution (25 B6.) 40 40 The material is dried, steamed for about 2 minutes in a Mather-Flatt apparatus, washed, treated with boiling soap solution and rinsed.

There are obtained respectively pink and violet patterns on a black ground. Instead of the alkali salts of non-volatile organic acids indicated in the examples there may,

be used other similar alkali salts, such as sodium glycolate, sodium tartrate and sodium oxalate.

It is to be noted that with an analogous result in this process the fabric may be first printed with the color resist and only afterwards, but before steaming, treated with the aniline black padding preparation.

Instead of the ester salts of leuco-vat-dyestuffs named in these examples, leuco-ester salts of other vat-dyestuffs such as dimethoxy-dibenzanthrone, indanthrone, dyestuffs of the indigo and thioindigo series may be used.

What I claim is 2- I 1. A process for producing colored resists under aniline black by means of ester salts of leuco-vatdyestuffs, wherein a color resist printing paste containing an ester salt of a leuco-vat-dyestuif, an alkali salt of a non-volatile organic acid and aluminium chlorate, is printed on the fabric, this latter being treated with an aniline black padding preparation in any phase previous to steaming, the fabric is dried and finally steamed for about 2 minutes in order to develop simultaneously the ground color and the resist effects.

2. A process for producing colored resists under aniline black by means of ester salts of leuco-vatdyestuffs, wherein the material is padded with an aniline black padding preparation, dried, then printed with a color resist printing paste containing an ester salt of a leuco-vat-dyestuff, an alkali salt of non-volatile organic acid and aluminium chlorate, again dried and finally steamed for about 2 minutes in order to develop simultaneously the ground color and the resist effects.

' 3. A process for producing colored resists under aniline black by means of ester salts of leuco-vatdyestuffs, wherein a color resist printing paste containing an ester salt of a leuco-vat-dyestuif, an alkali salt of a non-volatile organic acid and aluminium chlorate is printed on the fabric, this latter is afterwards treated with an aniline black padding preparation, dried and finally steamed for about 2 minutes in order to develop simultaneously the ground color and the resist effects.

4. A process for producing colored resists under aniline black by means of ester salts of a leucovat-dyestuffs, wherein a color resist printing paste containing an ester salt of leuco-dibenz-pyrenequinone, an alkali salt of a non-volatile organic acid and aluminium chlorate is printed on the fabric, this latter being treated with an aniline black padding preparation in anyphase previous to steaming, the fabric is dried and finally steamed for about 2 minutes in order to develop simultaneously the ground color and the resist effects.

5. A process for producing colored resists under aniline black by means of ester salts of leuco-vatdyestuffs, wherein a color resist printing paste containing an ester salt of leuco-dimethoxy-dibenzanthrone, an alkali salt of a non-volatile organic acid and aluminium chlorate is printed on the fabric, this latter being treated with an aniline black padding preparation in any phase previous to steaming, the fabric is dried and finally steamed for about 2 minutes in order to develop simultaneously the ground color and the resist effects.

6. A process for producing colored resists under aniline black by means of ester salts of leuco-vatdyestuffs, wherein a color resist printing paste containing an ester salt of leuco-4z4'-dimethyl- 6:6'-dichloro-thioindigo, an alkali salt of a nonvolatile organic acid and aluminium chlorate is printed on the fabric, this latter being treated with an aniline black padding preparation in any phase previous to steaming, the fabric is dried and finallysteamed for about 2 minutes in order to develop simultaneously the ground color and'the resist effects.

'7. A process for producing colored resists under aniline black by means of ester salts of leuco-vatdyestuffs, wherein a col-or resist printing paste containing an ester salt of a leuco-vat-dyestuff, sodium citrate and aluminium chlorate is printed on the fabric, this latter being treated with an aniline black padding preparation in any phase previous to steaming, the fabric is dried and finally steamed for about 2 minutes in order to develop simultaneously the ground color and the resist effects.

v 8. A process for producing colored resists under aniline black by means of ester salts of leuco-vatdyestuffs, wherein a color resist printing paste containing an ester salt of a leuco-vat-dyestuff,

sodium tartrate and aluminium chlorate is printed on the fabric, this latter being treatedwith an aniline black padding preparation in any phase previous to steaming, the fabric is dried and finally steamed for about 2 minutes in order. to

develop simultaneously the ground color and the 

